When we switch from emulated PS/2 to native (RMI4 or Elan) protocols, we
create SMBus companion devices that are attached to I2C/SMBus controllers.
However, when suspending and resuming, we also need to make sure that we
take into account the PS/2 device they are associated with, so that PS/2
device is suspended after the companion and resumed before it, otherwise
companions will not work properly. Before I2C devices were marked for
asynchronous suspend/resume, this ordering happened naturally, but now we
need to enforce it by establishing device links, with PS/2 devices being
suppliers and SMBus companions being consumers.
Fixes: 172d931910e1 ("i2c: enable async suspend/resume on i2c client devices")
Reported-and-tested-by: Hugh Dickins <hughd@xxxxxxxxxx>
Tested-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/input/mouse/psmouse-smbus.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/input/mouse/psmouse-smbus.c b/drivers/input/mouse/psmouse-smbus.c
index a472489ccbad..164f6c757f6b 100644
--- a/drivers/input/mouse/psmouse-smbus.c
+++ b/drivers/input/mouse/psmouse-smbus.c
@@ -75,6 +75,8 @@ static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
"Marking SMBus companion %s as gone\n",
dev_name(&smbdev->client->dev));
smbdev->dead = true;
+ device_link_remove(&smbdev->client->dev,
+ &smbdev->psmouse->ps2dev.serio->dev);
serio_rescan(smbdev->psmouse->ps2dev.serio);
} else {
list_del(&smbdev->node);
@@ -174,6 +176,8 @@ static void psmouse_smbus_disconnect(struct psmouse *psmouse)
kfree(smbdev);
} else {
smbdev->dead = true;
+ device_link_remove(&smbdev->client->dev,
+ &psmouse->ps2dev.serio->dev);
psmouse_dbg(smbdev->psmouse,
"posting removal request for SMBus companion %s\n",
dev_name(&smbdev->client->dev));
@@ -270,6 +274,12 @@ int psmouse_smbus_init(struct psmouse *psmouse,
if (smbdev->client) {
/* We have our companion device */
+ if (!device_link_add(&smbdev->client->dev,
+ &psmouse->ps2dev.serio->dev,
+ DL_FLAG_STATELESS))
+ psmouse_warn(psmouse,
+ "failed to set up link with iSMBus companion %s\n",
+ dev_name(&smbdev->client->dev));
return 0;
}
--
2.35.1.265.g69c8d7142f-goog
--
Dmitry
